=== modified file 'dhis-2/dhis-services/dhis-service-core/src/main/java/org/hisp/dhis/dataset/CompleteDataSetRegistrationDeletionHandler.java'
--- dhis-2/dhis-services/dhis-service-core/src/main/java/org/hisp/dhis/dataset/CompleteDataSetRegistrationDeletionHandler.java	2015-01-17 07:41:26 +0000
+++ dhis-2/dhis-services/dhis-service-core/src/main/java/org/hisp/dhis/dataset/CompleteDataSetRegistrationDeletionHandler.java	2015-01-22 17:10:43 +0000
@@ -28,6 +28,7 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+import org.hisp.dhis.dataelement.DataElementCategoryOptionCombo;
 import org.hisp.dhis.organisationunit.OrganisationUnit;
 import org.hisp.dhis.period.Period;
 import org.hisp.dhis.system.deletion.DeletionHandler;
@@ -88,4 +89,12 @@
     {
         completeDataSetRegistrationService.deleteCompleteDataSetRegistrations( unit );
     }
+
+    @Override
+    public String allowDeleteDataElementCategoryOptionCombo( DataElementCategoryOptionCombo optionCombo )
+    {
+        String sql = "SELECT COUNT(*) FROM completedatasetregistration where attributeoptioncomboid=" + optionCombo.getId();
+        
+        return jdbcTemplate.queryForObject( sql, Integer.class ) == 0 ? null : ERROR;
+    }
 }